Fortunately, I was able to solve the problem with Amazon myself – my orderer book had been blocked after a small content improvement and re-upload. However, I know from experience that this is the exception, especially once a book is blocked. I had contacted PSA Marketing and was positively impressed how quickly a response came from Mr. Safer, who listened to the issue and I was able to discuss in a phone call how we would proceed in the event the book was not unlocked after 2 days. That was very reassuring to know that there is a company that takes care of such cases. I can’t say anything about the price, since I was able to solve the problem myself. But in my case, they would have certainly been worth the money. I can therefore happily recommend this company to KDP authors and Amazon merchants.